Single-precision-safe OIFS/OASIS coupling + XIOS output - #1029
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Type the OASIS exchange buffer exfld as WP_full (always double) and route every FESOM-internal coupling MPI call through MPI_WP so USE_SINGLE_PRECISION (WP=real32) coupled builds no longer pass MPI_DOUBLE_PRECISION for real(kind=WP) buffers. Make the XIOS tracks/grid coordinate paths double (io_tracks/io_xios). Relax the CMake guard to allow SP for the OIFS-via-OASIS combination.
…-coupled # Conflicts: # src/io_tracks.F90
…nto feat/single-precision-coupled
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I did some test runs. It works in AWI-ESM3. Yet to test speedup. |
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I did a short test with core3 coupled to tco95.
Works. Not optimized at all. But i see substantial speedup in this short test already. |
suvarchal
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Aug 31, 2026
suvarchal
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Aug 31, 2026
kind=8 is not portable (NEC compilers number real kinds 1,2,3). Switch the double-precision geometry declarations and the two xios_duration literals to the WP_full parameter (=real64), which is defined portably in o_param. Addresses review feedback on PR #1029.
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Makes
USE_SINGLE_PRECISION(WP=real32) work in coupled OIFS-via-OASIS builds.cpl_driver.F90
exfldtypedWP_full(always double), matching theoasis_Doubletransient and mirroring OpenIFS' dedicated double coupling kind JPRO.MPI_WPinstead of hardcodedMPI_DOUBLE_PRECISION, so the MPI type tracks WP.gen_forcing_couple.F90
integrate_2Dreductions useMPI_WP. The raw FESOM<->atmosphere net-flux exchange innet_rec_from_atmis left double (skipped for__oifs) with an explanatory note.io_tracks.F90 / io_xios.F90
real(kind=8)/ matchingmod_tracks_geometryTG_WP), so SP + XIOS compiles.CMakeLists.txt
OASIS accepts single-precision buffers (its put/get and grid-write interfaces are generic over real4/real8 and promote to double internally), so nothing is corrupted when WP=real32; the genuine breakage was FESOM's own hardcoded double MPI calls on
real(kind=WP)buffers.Draft: builds and initializes coupled; runtime coupled validation on albedo (AWI-ESM3 TCO95/CORE3, single precision) in progress.